Audience measurement systems typically include one or more site meters to monitor the media presented by one or more media devices located at a monitored site. Many such audience measurement systems also include one or more people meters to obtain information characterizing the composition(s) of the audience(s) in the vicinity of the media device(s) being monitored. In prior audience measurement systems, the people meters typically are separate from the site meters, or employ different signal processing technology than that employed by the site meters. For example, the site meters may be configured to process media signals captured from the monitored media devices to detect watermarks embedded in the media signals, whereas the people meters may be configured to capture and process images of an audience, and/or process input commands entered by members of the audience.
Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts, elements, etc.